son and Goebel,* but it seems to have been first clearly 
recognized by Mrs. Kellerman (9) who postulated that 
the ear has developed phylogenetically from the central 
stem of the primitive tassel. Montgomery (14) appar- 
ently unaware of Mrs. Kellerman’s suggestion, inde- 
pendently arrived at the same conclusion, illustrating it 
with an interesting series of transition stages to show how 
the change from a staminate central spike of the tassel 
to a pistillate ear might have occurred. 
Since the appearance of Montgomery’s paper the 
homology of the ear with the central spike of the tassel 
has not been seriously challenged except, perhaps, by 
indirection. Strong evidence, amounting almost to proof, 
of the homology of the two structures has recently been 
furnished by Langham (11) who showed that in segre- 
gates of maize-teosinte hybrids there is a close correla- 
tion between the ear and the central spike of the tassel 
in the expression of distichy and polystichy. A recent 
paper by Bonnett (8) is illustrated with striking photo- 
graphs which reveal, among other things, that in the 
early stages of development the two structures, ear and 
central spike, are scarcely distinguishable. 
Anderson (1) has recently pointed out that some of the 
important characteristics of the ear are closely correlated 
with characteristics of the lateral branches of the tassel. 
These observations, as will be shown later, are not in 
conflict with the conception of the ear as the homologue 
of the central spike of the tassel. 
The fact that the ear is the homologue of the central 
spike does not, however, solve the problem of the origin 
of the ear. As Collins (4) pointed out many years ago, 
* Cf, Weatherwax (19) or Mangelsdorf and Reeves (13) for refer- 
ences. 
t Italics hers. 
[ 36 ] 
